Photo help

I'm trying to free space on my iPhone 6 plus can someone help am I safe to delete all my camera roll? Does it auto back up to iCloud? I have this activated - so if I delete a photo will it also delete from iCloud ?

Don't do that. I would use cloud based apps like Box, Dropbox and OneDrive. Upload photos to those apps, then delete the photos from your camera roll. You can set up photo folders and subfolders to organize your photos. Videos too. You could use iCloud Photo Library, but it uses up your iCloud storage space you need for back up. Box offers 10 free gb of storage. OneDrive offers 30 free gb of storage. Why are you needing to free space? What else do you have on your phone that's taking space? Music? Messages?

This is the issue not sure where all my memory is being used up 600Mb of memory on photos - I've got a 200gb iCloud Drive account just worried that deleting the snaps will also delete off the cloud - so you recommend both?

If you delete pictures from your phone, they will also be deleted from iCloud. It's better to take Ledsteplin's advice. I personally like Carousel by Dropbox, because it notifies when you can free up space from your device. It deletes them than from your device, after it has backupped them to Dropbox

Is this a 16 gb phone? If so, delete a bit of everything. You don't really have all that much photos. Delete your emails. Delete apps you don't need. Delete Twitter to get rid of the cache. Then download it back. How much available storage space do you have on your phone? Not iCloud storage. Go to Settings >General >About >look for available Storage.